KR20060013571A - Newsprint paper treated with cationic surface-sizing agent - Google Patents

Abstract

Newsprint paper for offset printing which has satisfactory resistance to water absorption and little causes color deviation in offset printing to give clear printed surfaces can be produced by applying a surface treatment comprising as the main components (A) a water-soluble high- molecular substance selected from among starches, PVA's, polyacrylamides, and cellulose derivatives and (B) a copolymer obtained by copolymerization of a styrenic monomer with a cationic monomer, a water-soluble copolymer obtained by copolymerization of a styrenic monomer with a cationic monomer and a hydrophobic monomer, or a water- soluble copolymer obtained by treating such a copolymer obtained by using a monomer bearing a tertiary amino group as the cationic monomer with a quaternizing agent to newsprint base paper produced with the addition in paper making of less than 3.0 wt% of aluminum sulfate (a product with an Al2O3 .14H2O content of 50wt%).

Description

Newspaper sized with cationic surface size zero {NEWSPRINT PAPER TREATED WITH CATIONIC SURFACE-SIZING AGENT}

TECHNICAL FIELD This invention relates to newsprint paper which improved absorption resistance, especially newsprint paper for offset printing.

In recent years, the printing technology has made great advances such as offset printing, color printing, high speed mass printing, and automation. In connection with this, the improvement of various physical properties is calculated | required also with respect to print paper from a workability and a printability.

Newspaper printing paper is paper mainly composed of mechanical pulp (hereinafter referred to as MP) or deinking pulp (hereinafter referred to as DIP), and is classified into middle and lower paper. However, the printing of newspaper paper needs to reliably print a specified number of copies within a designated time in a designated time zone, and the newspaper printing paper is a paper in which strict quality is required more than that of ordinary printing paper. In recent years, newspaper printing papers are required to be lighter in weight, higher in DIP blending, and the like, and various improvements need to be made while overcoming these negative aspects. Thus, the improvement of newspaper printing paper is a strict different from the improvement of general printing paper.

The printing method of newspapers has been shifted to offset printing with the introduction of a computer system, and now, the offset printing method has taken the majority. In addition, with the spread of offset color printing machines such as satellite type and tower press type, the color of newspaper is also increasing. With the recent spread of four-color color offset printing, the deposition amount of the condensed water is about four times, and the newspaper paper swells due to the transfer of the condensed water, and the shift of dots is generated, The problem of the color shift which makes an image unclear becomes easy to arise.

With the spread of this offset printing, newspaper papers are required to have different quality, for example, the following quality from newsprint paper for iron plate printing.

(1) It has wet strength and no water drainage.

(2) Absorption resistance should be maintained properly.

(3) Peeling strength (adhesiveness) is small.

(4) There should be no paper dust.

Among these required qualities, in particular, the provision of absorption resistance (that is, the provision of size) is an important problem.

In addition to this offset printing method, non-GP, neutral papermaking, and weight reduction of newspaper papers due to the high mixing ratio of DIP are also factors that make the fibers easy to swell and cause color deterioration.

Background Art In recent years, so-called neutral paper paper, which is frigidated in the neutral to slightly alkaline pH range, has become a big trend due to quality demands such as high whitening of newspaper paper and improvement of the sharpness of color printing surfaces. By this neutral papermaking, the addition rate of alumina sulfate at the time of newspaper printing paper deterioration was reduced, and it was used in the paper of the newspaper printing paper (hereinafter, referred to as acid paper printing paper) which was made of acid paper. There exists a tendency for the effect (providing water absorption resistance) of a surface size agent to reduce. The surface sizing agent used in acidic newspaper printing paper is generally a copolymer of a monomer containing a carboxyl group and a styrene monomer. By the interaction of the carboxyl group in the surface sizing agent molecule with the aluminum component in the base paper of the newspaper, the surface sizing agent molecule is formed so that the hydrophilic monomer part having the carboxyl group is inside the paper and the hydrophobic styrene monomer part is the surface of the paper. It is thought to orientate and to provide absorption resistance to newspaper printing paper. However, in a newspaper printing paper base paper having a low addition rate of aluminum sulfate, particularly a newspaper printing paper base paper made of neutral paper (hereinafter, referred to as a neutral newspaper printing paper base), the orientation of the surface size agent is as much as that of an acidic newspaper printing paper. Since it is not perfect, absorption resistance is drastically reduced compared with the same application amount of the said surface size agent.

As described above, it was difficult to give the neutral newsprint paper the same absorption resistance as the acid newsprint paper with the conventional surface sizing agent used in the acid newsprint paper. In addition, in acidic newsprint paper, a new improvement in absorption resistance is desired.

As a method of controlling the absorption resistance of a newspaper printing paper, there are a method of adding a size agent internally (internal addition size) and a method of externally adding a chemical agent (external addition size) similarly to general printing paper. Internal addition means the method of adding a chemical | medical agent to a pulp slurry, and containing a chemical | medical agent in paper inside simultaneously with papermaking. External addition is the method of apply | coating a chemical | medical agent to a surface of a base paper using coating machines, such as a 2 roll size press and a gate roll coater, after papermaking.

As a general internal addition sizing agent, in the case of acidic papermaking, a reinforced rosin sizing agent, an emulsion sizing agent, a synthetic sizing agent, etc. are used, and in the case of neutral papermaking, an alkyl ketene dimer (hereinafter referred to as AKD) and an alkenylsuccinic anhydride ( Hereinafter referred to as ASA). In the method of internally adding such a size agent, there exist many problems as follows.

(1) It is necessary to add chemicals to the low concentration pulp slurry.

(2) The amount of fixation of the chemical to the pulp sheet is not constant (the amount of fixation of the chemical is low).

(3) When a plurality of paper machines use a common circulating white water, paper that does not require absorption resistance cannot be performed in parallel.

(4) The effect of the yield improver is not stable. When the yield is increased, colored foreign substances derived from DIP and the like float on the sheet.

(5) Absorption resistance changes over time.

(6) In a high speed paper machine which is used for neutral papermaking or a lightweight newspaper, the yield of the internal addition size agent tends to decrease, making it difficult to impart absorption resistance.

(7) In papermaking machines that produce a newspaper sheet containing 80% or more of DIP at a high speed of 1,000 m / min or more, the yield of the internally-added size agent tends to decrease, and it is difficult to impart absorption resistance.

For this reason, in the method of adding a size agent internally, it is difficult to control the addition amount of a size agent, and it was necessary to increase or decrease the addition amount of an internal addition size agent and a yield improving agent depending on a situation. In the case of poor efficacy of the internally added sizing agent, the internally added sizing agent is excessively added, and is likely to cause marked white water contamination, which is caused by a decrease in the intellect, adhesion and accumulation of hydrophobic sizing agents, and the like. There was a problem.

[0003] In the initial stage for frying newspaper printing paper, a gate roll coater is usually provided as a facility for applying a chemical to the surface of a newspaper printing paper base paper. As a conventional technique of imparting absorption resistance to newsprint papers by external addition of a sizing agent, as described above, in the case of acidic newsprint papers, a styrene-based surface size which is a copolymer of a monomer containing a carboxyl group and a styrene-based monomer I am commonly used. However, even if this styrene-based surface size agent is applied to a newspaper printing paper base paper having a low alumina sulfate addition rate, especially a neutral newspaper printing paper base, sufficient absorption resistance cannot be obtained.

MEANS TO SOLVE THE PROBLEM The present inventors continuously examined the provision of the absorption resistance to the newspaper printing paper by the external addition of a sizing agent, and have already applied the following applications. The following application describes a technique of forming a coating layer containing an absorbent control composition mainly composed of three components, Component A, Component B, and Component C, on a printing paper base paper (particularly, newspaper printing paper). Component A: chemical starch or starch, component B: nonionic polyacrylamide, cationic polyacrylamide having a tertiary amine group, cationic polyacrylamide having a quaternary ammonium group, at least 1 selected from amphoteric polyacrylamide The polyacrylamide of component, component C: the anionic copolymer of the monomer which has a weight average molecular weight of 0.1 million-3 million, and has a C6-C10 hydrophobic substituent, and the monomer which has a carboxyl group or a sulfonic acid group (refer patent document 1). Neutrality which expresses size degree by externally adding a ketene dimer-based sizing agent and a paper surface processing agent to a neutral roll paper using calcium carbonate as a filler with a gate roll coater, and then passing it through a soft calender having a surface temperature of 50 ° C or higher. The manufacturing method of newspaper printing paper is described (refer patent document 2). A technique of forming a coating layer containing an absorbent control composition mainly composed of two components A and B on a printing paper base paper (particularly, newspaper printing paper base paper), and having a droplet absorption of 10 to 1,000 seconds is described. . Component A: at least one polyacrylamide selected from nonionic polyacrylamide, cationic polyacrylamide, amphoteric polyacrylamide, component B: monomers having a hydrophobic substituent and a monomer having a carboxyl group and / or a sulfonic acid group Thermophilic copolymer (refer patent document 3). The three component components which consist of the component A, the component B, and the component C shown below, or the two components which consist of the component B and the component C mainly have a solid content weight ratio of each component A: B: C = 0-80: 95-20 DESCRIPTION OF RELATED ART The technique which forms the coating layer containing the surface size agent which is 1-10 on a newspaper printing paper base paper is described. Component A: at least one polyacrylamide selected from nonionic polyacrylamide, cationic polyacrylamide, amphoteric polyacrylamide, component B: anionic air of a monomer having a hydrophobic substituent and a monomer having a carboxyl group At least one member selected from ammonium salts of a coalesce, component C: dehydroabietic acid, abietinic acid, dihydroaviertic acid, fimaric acid, neopimaric, isopimaric acid, repopimaric acid, parastrin Rosin containing resin acid or these resin acids (refer patent document 4).

For the purpose of imparting absorption resistance, the surface size agent used in the present invention and the surface size agent used in the present invention are common, but the surface size agent used in the present invention is a novel one having a different composition.

In addition, to improve the surface strength and water resistance of newspaper printing papers for the purpose of preventing the deposition of paper powder on a blanket and the resulting printing streaks in offset printing using relatively strong printing inks. There is a prior art shown below.

In an offset printing newspaper paper formed by applying and drying an aqueous liquid containing a surface treating agent on a base paper, the surface treating agent comprises at least a polyacrylamide polymer and an epoxy water-resistant or polyvalent metal compound-based water-resistant agent. A newspaper sheet for offset printing is disclosed (see Patent Document 5). An offset printing newspaper paper obtained by coating a surface treatment agent on a paper containing a filler added therein, wherein the surface treatment agent contains a polyvinyl alcohol polymer having a silanol group. Paper (see Patent Document 6). An offset printing newspaper paper obtained by applying and drying a surface treatment agent on a base paper, wherein the surface treatment agent is mainly composed of a synthetic resin latex having a gel content of 90% by weight or more (see Patent Document 7). Offset printing newsprint paper obtained by applying and drying a surface treatment agent on a base paper, wherein the main component of the surface treatment agent is copolymer latex, and a release agent is contained in the surface treatment agent (see Patent Document 8). ). An offset printing newsprint obtained by applying and drying a surface treatment agent on both sides of a base paper, wherein the main component of the surface treatment agent is an acrylic alkali-swelling synthetic resin latex (see Patent Document 9). In an offset printing newsprint obtained by applying and drying a surface treatment agent on both sides of a sheet of paper, the surface treatment agent includes (a) starch or modified starch, and (b) butyl (meth) acrylate and / or (meth) as a monomer composition. Offset having a hydrophobic acrylic surface sizing agent having a glass transition point of acryl 2-ethylhexyl of 10 ° C. or less as a main component, and the ratio of the starch component and the hydrophobic acrylic surface sizing agent as a solid content weight ratio of 100: 3 to 100: 30. Newsprint for printing (Patent Document 10).

[Patent Document 1] Japanese Patent No. 2939971

[Patent Document 2] Japanese Patent No. 2980833

[Patent Document 3] Japanese Patent No. 3093965

[Patent Document 4] Japanese Patent No. 3303291

[Patent Document 5] Japanese Unexamined Patent Publication No. 10-259591

[Patent Document 6] Japanese Unexamined Patent Publication No. 11-21790

[Patent Document 7] Japanese Unexamined Patent Publication No. 11-50393

[Patent Document 8] Japanese Unexamined Patent Publication No. 11-158795

[Patent Document 9] Japanese Unexamined Patent Publication No. 2000-17597

[Patent Document 10] Japanese Unexamined Patent Publication No. 2002-294588

SUMMARY OF THE INVENTION The problem to be solved by the present invention is to provide offset printing newsprint paper having sufficient absorption resistance, less color change during offset printing and clear printing surface, and particularly providing neutral newsprint paper for offset printing having sufficient absorption resistance. Is in.

Newspaper printing paper A surface treatment agent containing the following components (A) and (B) as a main component is applied, dried, and calendered to obtain newsprint paper for offset printing.

Component (A): At least 1 type or more water-soluble high molecular material chosen from starch, polyvinyl alcohol, polyacrylamide, and a cellulose derivative.

Component (B): In the copolymer obtained by copolymerizing the following component (a) and component (b), or the copolymer obtained by copolymerizing component (a), component (b) and component (c), or in these copolymers. The water-soluble surface size agent which is a copolymer which quaternized the copolymer which used the tertiary amine group containing vinyl monomer as a component (b). It is preferable that the cation degree is 1.3-3.0 meq / g. More preferably, it is 1.3-2.5 meq / g, Most suitably 1.4-2.0 meq / g.

Component (a): Styrene monomer

At least one styrene monomer selected from styrene, α-methylstyrene, chlorostyrene, and cyanostyrene.

Component (b): Cationic Monomer

Vinyl monomer containing any one of a primary amino group, a secondary amino group, a tertiary amino group, and a quaternary ammonium group.

Component (c): other hydrophobic monomer

At least one hydrophobic monomer selected from methacrylic acid esters and acrylic acid esters as a monomer copolymerizable.

Ingredient (d): Quaternary

At least one quaternizing agent selected from epichlorohydrin, vinyl chloride, ethyl chloride, benzyl chloride, dimethyl sulfuric acid, diethyl sulfuric acid, oxides, epoxy compounds, and organic halides.

MEANS TO SOLVE THE PROBLEM The present inventors find it difficult to provide absorption resistance to newsprint paper with low alumina sulfate addition rate to pulp at the time of agitation, especially neutral newsprint paper, because the cationic aluminum component has a small content in the newsprint paper. By externally adding a cationic surface sizing agent having a specific ionic strength and a specific ionic strength, the present inventors have found that the absorbent resistance can be effectively imparted to the base paper of newspaper printing paper.

The newspaper printing paper base used in the present invention may be an acid newspaper printing paper base paper or a neutral newspaper printing paper base paper, and the addition rate of alumina sulfate to absolute dry pulp is 3.0% by weight (Al ₂ O ₃ .14H ₂ O. When the surface treatment agent containing the surface size agent of the present invention is applied to a newspaper printing paper base material of less than 50% by weight), the effect of imparting absorption resistance is greatly expressed. Neutral newspaper printing paper is preferable in this respect. The basis weight of the base paper of a newspaper printing paper is not particularly limited, but is preferably about 33 to 45 g / m 2.

The cationic surface size agent used by this invention is obtained by copolymerizing a styrene-type monomer (component (a)) and a cationic monomer (component (b)). Or it is obtained by copolymerizing a styrene monomer (component (a)), a cationic monomer (component (b)), and another hydrophobic monomer (component (c)). Or the copolymer using the tertiary amine group containing vinyl monomer as a component (b) among these copolymers is obtained by quaternizing with the component (d).

It is preferable that the cationization degree of the surface size agent obtained in this way is 1.3-3.0 meq / g. More preferably, it is 1.3-2.5 meq / g, Most suitably 1.4-2.0 meq / g. By apply | coating the surface treating agent containing this surface size agent, sufficient water absorption resistance (degree of size) can be given to the newspaper printing paper base paper. If it is less than 1.3 meq / g, the coating property of the pulp fiber is inferior, and if it exceeds 3.0 meq / g, the hydrophilicity is too strong and sufficient absorption resistance cannot be obtained.

The composition of the surface size agent used by this invention is demonstrated.

The styrene monomer of the component (a) is at least one styrene monomer selected from styrene, α-methyl styrene, chlorostyrene, and cyano styrene.

The cationic monomer of component (b) is any one kind of cationic vinyl monomers of a primary amino group-containing vinyl monomer, a secondary amino group-containing vinyl monomer, a tertiary amino group-containing vinyl monomer, and a quaternary ammonium group-containing vinyl monomer. to be. As a primary amino group containing vinyl monomer, allylamine and metaarylamine are mentioned, for example. As a secondary amine group containing vinyl monomer, diallylamine and dimethylamine are mentioned, for example. As a monomer which has a tertiary amino group, there exists a vinyl compound which has a tertiary amino group, Specifically, the following are mentioned, for example.

(1) (dialkyl) aminoalkyl (meth) acrylate: For example, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, diethylamino Propyl (meth) acrylate and the like.

(2) (dialkyl) aminohydroxyalkyl (meth) acrylate: dimethylaminohydroxyethyl (meth) acrylate, diethylaminohydroxyethyl (meth) acrylate, dimethylaminohydroxypropyl (meth) acrylate , Diethylaminohydroxypropyl (meth) acrylate, and the like.

(3) (dialkyl) aminoalkyl (meth) acrylamide: dimethylaminopropyl (meth) acrylamide, diethylaminopropyl (meth) acrylamide and the like.

(4) vinylpyridine

(5) vinylimidazole

As a monomer which has a quaternary ammonium salt, what quaternized the monomer which has the said tertiary amino group with the quaternization agent is mentioned. As a quaternization agent used when obtaining the monomer which has a quaternary ammonium salt, methyl chloride, ethyl chloride, benzyl chloride, epichlorohydrin, alkylene oxide, styrene oxide, glycidyl trimethylammonium chloride, and 3-chloro-2 And epoxy compounds such as hydroxyammonium chloride, organic halides, dimethyl sulfuric acid, and diethyl sulfuric acid.

The hydrophobic monomer of the component (c) is a copolymerizable monomer and is at least one hydrophobic monomer selected from methacrylic acid esters and acrylic acid esters. As methacrylic acid ester, C1-C18, such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, octyl methacrylate, 2-ethylhexyl methacrylate, for example Cyclic alkyl methacrylates, such as alkyl methacrylate which has an alkyl group, cyclohexyl methacrylates, and benzyl methacrylate, etc. are mentioned. As acrylic acid ester, the alkyl acrylate which has a C1-C18 alkyl group, such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, octyl acrylate, and 2-ethylhexyl acrylate, cyclo, for example Cyclic alkyl acrylates, such as hexyl acrylate and benzyl acrylate, etc. are mentioned.

The quaternizing agent of component (d) is used when the monomer which has a tertiary amino group is used as component (b). A quaternizing agent is used to make the tertiary amine in the copolymer of component (a) and component (b) or in the copolymer of component (a), component (b) and component (c) as a quaternary ammonium. use. As this quaternization agent, for example, at least one quaternization agent selected from epichlorohydrin, methyl chloride, ethyl chloride, benzyl chloride, dimethyl sulfuric acid, diethyl sulfuric acid, oxides, epoxy compounds, and organic halides to be. The amount of the quaternizing agent added is the same as the cationic monomer of the component (b).

In this copolymer composition, the solid content weight ratio of the styrene monomer of the component (a) and the cationic monomer of the component (b) is preferably in the range of 80:20 to 20:80. More preferably, they are 80: 20-50: 50. If the proportion of the cationic monomer is less than 20%, the degree of cationization of the copolymer is low, and the effect of imparting absorption resistance is small. The higher the proportion of the cationic monomer, the higher the degree of cationicity of the copolymer, but the level of absorption resistance improvement is 80% or higher. Moreover, you may copolymerize a small amount of the other hydrophobic monomer of the component (c) in the range which does not interfere with absorption resistance. When the sum total of component (a) and component (b) is 100, component (c) is about 30 at maximum.

Copolymerization of component (a) and component (b), or copolymerization of component (a) with component (b) and component (c), comprises component (a) and component (b) or component (a) and component (b). ) And component (c). For example, in a lower alcohol organic solvent such as methyl alcohol, ethyl alcohol, isopropyl alcohol, or an oily organic solvent such as benzene, toluene or xylene, 1 to 10 at 60 to 130 ° C. using a radical polymerization catalyst. After the polymerization, the organic solvent is distilled off if necessary after the completion of the polymerization. The radical polymerization catalyst may be a known one and is not particularly limited, but is useful, for example, as 2,2'-azobisisobutylonitrile, dimethyl 2, 2'-azobis- (2-methylpropionate), or the like. Oil-soluble organic peroxides, such as a star-type azo catalyst, benzyl peroxide, tertiary butyl peroxy benzoate, and tertiary butyl peroxy-2-ethylhexanoate, etc. are mentioned. Moreover, you may use together well-known chain transfer agents, such as alkyl mercaptan suitably as needed.

The surface sizing agent is basically a copolymer of a hydrophobic monomer and a hydrophilic monomer, and is a high molecular material having an interfacial activity. Therefore, in aqueous solution, since the surface size agent forms intracellular micelles, it is possible to measure the particle diameter by the dynamic light scattering method. Although the surface sizing agent used in the present invention is water-soluble, the above-described phenomenon enables measurement of the average particle diameter by the dynamic light scattering method, and the average particle diameter by the dynamic light scattering method is 40 nm or less. The smaller average particle diameter results in a higher size effect because the fiber coverage per unit weight is higher, and the larger the average particle diameter becomes, the smaller the size effect becomes.

Although the detailed mechanism by which this copolymer composition gives absorption resistance is not clear, the present inventors estimate as follows. The cationic monomer portion in the surface size agent molecule is oriented inside the paper surface by interaction with the carboxyl group of the pulp, and hydrophobic groups such as styrene monomers in the surface size agent molecule are oriented outside the paper surface. In addition, it is estimated that the droplet absorption which is an index of absorption resistance becomes high.

This surface size agent is mixed with the water-soluble high molecular substance which is a binder similarly to the manufacturing method of a normal newsprint paper, it is made into a surface treating agent, and is coated on a newsprint paper. As a water-soluble high molecular substance, starches, such as starch, an enzyme modified starch, a thermochemical modified starch, oxidized starch, esterified starch, etherified starch (for example, hydroxyethylated starch, etc.), cationic starch, etc. Polyvinyl alcohols such as polyvinyl alcohol, fully saponified polyvinyl alcohol, partially saponified polyvinyl alcohol, carboxyl modified polyvinyl alcohol, silanol modified polyvinyl alcohol, cation modified polyvinyl alcohol, terminal alkyl modified polyvinyl alcohol And polyacrylamides such as polyacrylamide, cationic polyacrylamide, anionic polyacrylamide, and amphoteric polyacrylamide, and cellulose derivatives such as carboxymethyl cellulose, hydroxyethyl cellulose and methyl cellulose. These are used individually or in mixture of 2 or more types. The use of these water-soluble high molecular materials is important in increasing the surface strength of newsprint and suppressing the occurrence of equity in printing.

The amount of the water-soluble polymer substance is determined by the target value of the surface strength of the newsprint paper, and the amount of the cationic styrene-based size agent used in the present invention is mainly determined by the target value of the absorption resistance of the newsprint paper. In this regard, there is no particular regulation on the blending ratio of the water-soluble polymer material and the surface size agent. However, the cationic styrene-based size agent used in the present invention is usually 1 to 50 parts by weight based on 100 parts by weight of the water-soluble polymer material. Preferably it is 15-40 weight part, More preferably, it is 20-40 weight part.

Among the surface treatment agents used in the present invention, there are no adverse effects on the absorption resistance, which is the effect of the present invention, anti-viscosity agent, antiseptic agent, antifoaming agent, lubricant, anti-glare agent, anti-UV agent, anti-fading agent, fluorescent brightener, viscosity stabilizer and the like. And other surface size agents (styrene-acrylic acid copolymer, styrene-maleic acid copolymer, olefin copolymer, etc.) may be contained.

Newspaper printing paper base used in the present invention is MP such as ground pulp (GP), thermo mechanical pulp (TMP), chemical thermo mechanical pulp (CTMP), semi-chemical pulp (SCP), kraft pulp (KP), Chemical pulp (CP) represented by the pulping pulp (SP), deinking pulp (DIP) obtained by deinking old paper containing these pulp, and recovered pulp obtained by dissociating the waste sheet from the papermaking process, etc. The mixture is mixed alone or in an arbitrary ratio, and is paper-making by a well-known common paper machine. From the viewpoint of the demand for high compounding of DIP due to the recent increase of interest in environmental protection, the blending ratio of DIP is preferably in the range of 50 to 100% by weight.

Newspaper printing paper base paper of the present invention, if necessary, white carbon, clay, silica, talc, acidic titanium, calcium carbonate, synthetic resin filler (vinyl chloride resin, polystyrene resin, urea formalin resin, melamine resin, styrene, Butadiene-based copolymer-based resin and the like) can be used. In addition, a polyacrylamide-based polymer, a polyvinyl alcohol-based polymer, cationic starch, urea formalin resin, melamine formalin resin, internal additive strength enhancers, salts of copolymers of acrylamide and aminomethylacrylamide, cationic starch, Filtration and / or yield improvers such as polyethyleneimine, polyethylene oxide, acrylamide and sodium acrylate copolymer, rosin-based sizing agent, AKD, ASA, petroleum-based sizing agent, neutral rosin sizing agent, etc. And preparations such as fading inhibitors and the like.

What is necessary is just to apply the surface treating agent of this invention to the newspaper printing paper base paper mentioned above with the normal papermaking coating apparatus. For example, apparatuses, such as a 2 roll size press, a blade metal ring size press, a rod metal ring size press, a gate roll coater, a bar coater, an air knife coater, and a spray coater, are mentioned. Among these devices, a film transfer type coater represented by a gate roll coater is preferable, and in the case of newspaper printing paper, a gate roll coater (GRC) is common among these devices and is most preferably used in the present invention.

The coating speed at the time of coating the surface treating agent of this invention should just be about the initial speed of the paper machine which can manufacture a normal newspaper printing paper, and there is no limitation in particular, Usually, it is the range of 800-2500 m / min. By coating at a high speed of 800 m / min or more, since the surface treatment agent dries before sufficiently penetrating into the layer, there are many surface treatment agents present in the vicinity of the surface layer, and more effectively the swelling of the fibers present in the paper surface layer when water is absorbed. It can be suppressed.

The coating amount of the surface treating agent used in the present invention should be determined in accordance with the quality of the newsprint paper for offset printing, and is not particularly limited, but the coating amount (per two sides) is preferably in the range of 0.05 to 2.0 g / m 2. When application amount is less than 0.05 g / m <2>, there exists a possibility that the surface strength of a newspaper printing paper may run short. On the other hand, when the coating amount is more than 2.0 g / m 2, there is a high possibility of causing a viscosity problem (adhesive problem caused by the transfer and accumulation of the coating material on the blanket when the newspaper paper is printed in large quantities) which is a problem peculiar to the offset paper for printing.

Newspaper printing paper of this invention, after apply | coating and drying a surface treating agent, it is preferable to perform calendering in order to obtain the paper thickness and smoothness suitable for offset printing. As a calendar, a normal hard nip calendar or a high temperature soft nip calendar (for example, summarized in paper pulp technique Times Vol.43, No. 1 (2000) p23, etc.) is mentioned. In light of the weight reduction of future newsprint, the soft nip calendar is more preferably used in the newsprint of the present invention. From the point of color printability, the surface treating agent of the present invention may be combined with a soft nip calendering treatment.

Hereinafter, although an Example is given and demonstrated this invention, of course, this invention is not limited to these. In addition, unless otherwise indicated, a part and% show a solid content part and solid content weight%, respectively.

<Production of newspaper printing paper original paper>

Base A: In a pulp slurry prepared by mixing and dissociating at a ratio of 50 parts of DIP, 30 parts of TMP, 10 parts of KP, and 10 parts of GP, and having 190 ml of freeness, calcium carbonate as a filler was 2.5 per weight of the absolute dry pulp. %, Aluminum sulfate 1.5% (Al ₂ O ₃ .14H ₂ O is 50% by weight), neutral paper-making with a Berbeformer paper machine, basis weight of no calender without internal addition size 42 g / M 2 of newspaper printing paper was obtained. The droplet absorbance was 3 seconds.

Base B: Pulp slurry prepared by mixing and dissociating at a ratio of 50 parts of DIP, 30 parts of TMP, 10 parts of KP, and 10 parts of GP, and having a high altitude of 190 ml, and containing talc as a filler 1.5% by weight with respect to absolute dry pulp. 42% by weight of aluminum calcined with aluminum sulfate (with 50% by weight of Al ₂ O ₃ .14H ₂ O), acidic paper-based with a Berbeformer paper machine, and no internal addition size. / M 2 of newspaper printing paper. The droplet absorbance was 5 seconds.

Base C: Mix and dissociate at a ratio of 50 parts of DIP, 30 parts of TMP, 10 parts of KP, and 10 parts of GP, and added talc as a filler to 1.5% by weight with respect to absolute dry pulp as a filler. Then, aluminum sulfate was added 3.5% (Al ₂ O ₃ .14H ₂ O was 50% by weight), acid-based paper was fed with a Berbeformer paper machine, and a newspaper printing of a basis weight of 42 g / m 2 of no calender without internal addition size was printed. Obtained paper stock. The droplet absorbance was 4 seconds.

<Raw material monomer of surface size agent>

The surface size agent used by the Example and the comparative example was manufactured by copolymerizing the material selected from each of the following monomers and quaternization agents as a raw material.

Component (a): Styrene-based monomer

a-1: Styrene

Component (b): Cationic Monomer

b-1: Dimethylaminoethyl methacrylate

b-2: Dimethyl methacrylate ethyl benzyl chloride

Component (c): other hydrophobic monomer

c-1: methyl methacrylate

c-2: isobutyl methacrylate

Ingredient (d): Quaternary

d-1: epichlorohydrin

In addition, needless to say, the solid content weight ratio of the styrene monomer / cationic monomer is in the range of 80/20 to 20/80.

<Cationization Degree of Surface Size Agent, Average Particle Diameter, and Measurement Method of Lipid>

(1) Degree of cationization: Using a Mutech Particle Charge Detector 03, titrating with 1/1000 sodium polysulfate (PVSK) at a prescribed degree, the point where the flow current became zero was determined as the end point.

(2) Average particle diameter: It measured by the dynamic light scattering method using Zetasizer 300HSa (Malvern).

(3) Droplet absorbance: According to Japan TAPPI No. 33 (absorption rate test method of absorbent paper), it was measured by the dropwise quantity of 1 µl. Droplet absorbance is an indicator of absorption resistance.

<Production of newspaper paper>

Example 1

The component (a-1) and the component (b-1) were copolymerized in the organic solvent in the solid content weight ratio of 80:20, and quaternized with the component (d-1) of the same molar amount as the component (b-1). Subsequently, the organic solvent was distilled off and the water-soluble surface size agent was obtained. This surface sizing agent was mixed with hydroxyethylated starch (trade name: Etylex-2025, manufactured by Staley) at a concentration of 6.0% at a rate of 20% relative to starch to prepare a surface treating agent. The obtained surface treating agent was coated on the newsprint paper A by a gate roll coater (coating speed: 1200 m / min, double-sided coating). The coating amount is 0.50 g / m 2 on both sides. This was processed with a hard nip calendar to obtain a newsprint paper for offset printing. The results are shown in Table 1.

Example 2

Component (a-1) and component (b-1) were copolymerized in the organic solvent in the solid content weight ratio of 80:20. Subsequently, the organic solvent was distilled off and the water-soluble surface size agent was obtained. This surface sizing agent was mixed with hydroxyethylated starch (trade name: Etylex-2025, manufactured by Staley) at a concentration of 6.0% at a rate of 20% relative to starch to prepare a surface treating agent. The obtained surface treating agent was coated on the newsprint paper A using a gate roll coater (coating speed: 1200 m / min, double-side coating). The coating amount is 0.50 g / m 2 on both sides. This was processed with a hard nip calendar to obtain a newsprint paper for offset printing. The results are shown in Table 1.

Example 3

The weight ratio of the solids content of the component (a-1), the component (b-1) and the component (c-1) was 60:30:10 and copolymerized. Subsequently, the organic solvent was distilled off and the water-soluble surface size agent was obtained. This surface sizing agent was mixed with hydroxyethylated starch (trade name: Etylex-2025, manufactured by Staley) at a concentration of 6.0% at a rate of 20% relative to starch to prepare a surface treating agent. The obtained surface treating agent was coated on the newsprint paper A using a gate roll coater (coating speed: 1200 m / min, double-side coating). The coating amount is 0.49 g / m 2 on both sides. This was processed with a hard nip calendar to obtain a newsprint paper for offset printing. The results are shown in Table 1.

Example 4

After copolymerization at 60:30:10 in the solid content weight ratio of component (a-1), component (b-1), and component (c-1), the same molar amount of component (d-1) as component (b-1) ) Was added to quaternized. Subsequently, the organic solvent was distilled off and the water-soluble surface size agent was obtained. This surface sizing agent was mixed with hydroxyethylated starch (trade name: Etylex-2025, manufactured by Staley) at a concentration of 6.0% at a rate of 20% relative to starch to prepare a surface treatment agent. The obtained surface treating agent was coated on the newspaper printing paper base paper A with a gate roll coater (coating speed: 1200 m / min, double-sided coating). The coating amount is 0.48 g / m 2 on both sides. This was processed with a hard nip calendar to obtain a newsprint paper for offset printing. The results are shown in Table 1.

Example 5

After copolymerization with the solid content weight ratio of component (a-1), component (b-1), and component (c-1) 60:30:10, the same molar amount of component (d-1) as component (b-1) ) Was added to quaternized. Subsequently, the organic solvent was distilled off and the water-soluble surface size agent was obtained. This surface sizing agent was mixed with hydroxyethylated starch (Etylex-2025, manufactured by Staley) at a concentration of 6.0% at a rate of 20% relative to starch to prepare a surface treatment agent. The obtained surface treating agent was coated on the newspaper printing paper base B with a gate roll coater (coating speed: 1200 m / min, double-sided coating). The coating amount is 0.48 g / m 2 on both sides. This was processed with a hard nip calendar to obtain a newsprint paper for offset printing. The results are shown in Table 1.

Comparative Example 1

It copolymerized with the solid content weight ratio of component (a-1) and component (b-1) being 95: 5. Subsequently, the organic solvent was distilled off and the water-soluble surface size agent was obtained. This surface sizing agent was mixed with hydroxyethylated starch (Etylex-2025, manufactured by Staley) at a concentration of 6.0% at a rate of 20% relative to starch to prepare a surface treatment agent. The obtained surface treating agent was coated on the newsprint paper A using a gate roll coater (coating speed: 1200 m / min, double-side coating). The coating amount is 0.55 g / m 2 on both sides. This was processed with a hard nip calendar to obtain a newsprint paper for offset printing. The results are shown in Table 1.

Comparative Example 2

The solid content weight ratio of component (a-1), component (b-1), and component (c-2) was made into 85: 5: 10 and copolymerized. Subsequently, the organic solvent was distilled off and the water-soluble surface size agent was obtained. This surface sizing agent was mixed with hydroxyethylated starch (Etylex-2025, manufactured by Staley) at a concentration of 6.0% at a rate of 20% relative to starch to prepare a surface treatment agent. The obtained surface treating agent was coated on the newsprint paper A using a gate roll coater (coating speed: 1200 m / min, double-side coating). The coating amount is 0.50 g / m 2 on both sides. This was processed with a hard nip calendar to obtain a newsprint paper for offset printing. The results are shown in Table 1.

Comparative Example 3

Component (a-1) and component (b-1) are emulsion-polymerized in an aqueous medium at a solid content weight ratio of 80:20, and are quaternized with the same molar amount of component (d-1) as component (b-1). The surface size agent of the water dispersion state (emulsion) was obtained. This surface sizing agent was mixed with hydroxyethylated starch (Etylex-2025, manufactured by Staley) at a concentration of 6.0% at a rate of 20% relative to starch to prepare a surface treatment agent. The obtained surface treating agent was coated on the newsprint paper A using a gate roll coater (coating speed: 1200 m / min, double-side coating). The coating amount is 0.52 g / m 2 on both sides. This was processed with a hard nip calendar to obtain a newsprint paper for offset printing. The results are shown in Table 1.

[Comparative Example 4]

Component (a-1) and component (b-1) were emulsion-polymerized in 80:20 solid content weight ratio in the aqueous medium, and the surface size agent of the water dispersion state (emulsion) was obtained. This surface sizing agent was mixed with hydroxyethylated starch (Etylex-2025, manufactured by Staley) at a concentration of 6.0% at a rate of 20% relative to starch to prepare a surface treatment agent. The obtained surface treating agent was coated on the newsprint paper A using a gate roll coater (coating speed: 1200 m / min, double-side coating). The coating amount is 0.48 g / m 2 on both sides. This was processed with a hard nip calendar to obtain a newsprint paper for offset printing. The results are shown in Table 1.

[Comparative Example 5]

Component (a-1) and component (b-1) were emulsion-polymerized in 80:20 solid content weight ratio in the aqueous medium, and the surface size agent of the water dispersion state (emulsion) was obtained. This surface sizing agent was mixed with hydroxyethylated starch (Etylex-2025, manufactured by Staley) at a concentration of 6.0% at a rate of 20% relative to starch to prepare a surface treatment agent. The obtained surface treating agent was coated on the newsprint paper A using a gate roll coater (coating speed: 1200 m / min, double-side coating). The coating amount is 0.49 g / m 2 on both sides. This was processed with a hard nip calendar to obtain a newsprint paper for offset printing. The results are shown in Table 1.

Comparative Example 6

Anionic ethylene-based surface sizing agent KN-520 (manufactured by Harimagsei Co., Ltd.), which is common in acidic newsprint paper, is used as the surface sizing agent. It was mixed with hydroxyethylated starch (Etylex-2025, Staley) to prepare a surface treatment agent. The obtained surface treating agent was coated on the newsprint paper A using a gate roll coater (coating speed: 1200 m / min, double-side coating). The coating amount is 0.48 g / m 2 on both sides. This was processed with a hard nip calendar to obtain a newsprint paper for offset printing. The results are shown in Table 1.

Comparative Example 7

After copolymerization with the solid content weight ratio of component (a-1), component (b-1), and component (c-1) 60:30:10, the same molar amount of component (d-1) as component (b-1) ) Was added to quaternized. Subsequently, the organic solvent was distilled off and the water-soluble surface size agent was obtained. This surface sizing agent was mixed with hydroxyethylated starch (Etylex-2025, manufactured by Staley) at a concentration of 6.0% at a rate of 20% relative to starch to prepare a surface treatment agent. The obtained surface treating agent was coated on the newspaper printing paper base paper C with a gate roll coater (coating speed: 1200 m / min, double-sided coating). The coating amount is 0.49 g / m 2 on both sides. This was processed with a hard nip calendar to obtain a newsprint paper for offset printing. The results are shown in Table 1.

Surface size agent manufacturing condition Surface size Paper Surface treatment agent application amount Drip absorbance Ingredient (a) Component (b) Component (c) Component (d) Cation Degree Average particle diameter meq / g Nm g / ㎡ second Example 1 80 20 molar amount equal to (b) 1.3 46 Base A 0.50 30 Example 2 80 20 1.3 43 Base A 0.50 35 Example 3 60 30 10 1.5 33 Base A 0.49 60 Example 4 60 30 10 molar amount equal to (b) 1.7 32 Base A 0.48 103 Example 5 60 30 10 molar amount equal to (b) 1.7 32 Circle B 0.48 95 Comparative Example 1 95 5 0.5 130 Base A 0.55 11 Comparative Example 2 85 5 10 0.5 152 Base A 0.50 10 Comparative Example 3 80 20 molar amount equal to (b) 1.1 184 Base A 0.52 9 Comparative Example 4 80 20 1.0 175 Base A 0.48 9 Comparative Example 5 80 20 1.0 173 Base A 0.49 7 Comparative Example 6 -1.2 20 Base A 0.48 9 Comparative Example 7 60 30 10 molar amount equal to (b) 1.7 32 Circle C 0.49 15

Since the newspaper printing paper of the present invention is excellent in absorbing resistance, it is possible to suppress swelling or elongation of fibers due to absorption of condensate at the time of offset printing, and there is no color change, and a clear printing surface can be obtained.

Claims (5)

Newsprint printing paper A newspaper paper for offset printing, which is obtained by applying, drying, and calendering a surface treatment agent containing, as a main component, the following component (A) and component (B). Component (A): At least 1 type or more water-soluble high molecular material chosen from starch, polyvinyl alcohol, polyacrylamide, and a cellulose derivative. Component (B): Copolymer obtained by copolymerizing following component (a) and component (b), or copolymer obtained by copolymerizing component (a), component (b) and following component (c), or these copolymers The water-soluble surface size agent whose intermediate component (b) is the copolymer which quaternized the copolymer using the tertiary amine group containing vinyl monomer with the following component (d). Component (a): Styrene-based monomer At least one styrene monomer selected from styrene, α-methylstyrene, chlorostyrene and cyanostyrene. Component (b): Cationic Monomer Vinyl monomer containing any one of a primary amino group, a secondary amino group, a tertiary amino group, and a quaternary ammonium group. Component (c): other hydrophobic monomer At least 1 type of hydrophobic monomer chosen from methacrylic acid ester and acrylic acid ester as a monomer which can be copolymerized. Ingredient (d): Quaternary At least one quaternizing agent selected from epichlorohydrin, vinyl chloride, ethyl chloride, benzyl chloride, dimethyl sulfuric acid, diethyl sulfuric acid, oxides, epoxy compounds and organic halides. The method of claim 1, The cationization degree of water-soluble surface size agent is 1.3-3.0 meq / g, The newsprint paper for offset printing characterized by the above-mentioned. The method according to claim 1 or 2, The average particle diameter of water-soluble surface size agent is 40 nm by the dynamic light scattering method, The newsprint paper for offset printing characterized by the above-mentioned. The method according to any one of claims 1 to 3, A newsprint paper for offset printing, characterized in that the addition rate of alumina sulfate to absolute dry pulp is less than 3.0% by weight (50% by weight as Al ₂ O ₃ · 14H ₂ O). The method according to any one of claims 1 to 4, Newspaper Paper for offset printing, characterized in that the original paper is impregnated with neutral paper.